1. Field of the Invention
The present invention pertains to a liquid level sensing switch manual actuator for confirming the operability of the switch, particularly in applications for determining the operability of liquid level sensing switches in storage tanks and vessel cargo tanks.
2. Background
In certain applications of liquid level sensing switches the liquid level sensing mechanism is inaccessible for actuation to confirm the operability of the switch. One such application is in regard to liquid level sensing switches used in the cargo tanks of crude oil and refined petroleum products tankers, for example. In order to comply with the requirements of regulatory authorities and to help minimize the risk of overfilling tanks it is desirable and necessary to confirm the operability of liquid level sensing switches so that cargo loading operations may be carried out properly.
However, human access to many cargo holds and storage tanks which contain flammable or toxic materials or an inert atmosphere is not possible or at least normally forbidden and it is therefore necessary to provide some type of actuator which is operable, at will, exterior of the tank to confirm the operability of a liquid level sensing switch disposed in the tank. It is to this end that the present invention is directed with a view to providing an actuator for actuating the float member of a liquid level sensing switch disposed in the cargo tank of a marine tanker or the like.